A number of entertainment robots for home use have been developed in recent years for commercial purpose. Installed with various external sensors such as a CCD (Charge Coupled Device) camera and a microphone, some of those entertainment robots are designated to recognize exterior circumstances based on outputs of such external sensors and behave autonomously based on recognition results.
If such entertainment robots can remember the names of new objects (including human beings, hereinafter, too) in association with these objects, they can communicate with users more smoothly, and in addition, they may be able to flexibly react to a variety of commands regarding an object other than objects of which names are registered beforehand, for example, “Kick the ball” issued by the user. Note that remembering the name of an object in association with the same object as described above, is expressed as “to learn the name, and such a function is referred to as a “name-learning function” hereinafter.
Further, if an entertainment robot can learn the name of a new object via dialog with an ordinary person by providing such a name-learning function in the entertainment robot as human beings do, it may be the most desirable from the viewpoint of its naturalness and it is expected that the entertainment property of the entertainment robot may increase much more.
There is a problem with conventional techniques, however, that it is difficult to let an entertainment robot judge whether the name of a new object showing up in front of itself should be learned.
Because of this, in the conventional techniques, a user issues a clear voice command or presses a particular touch sensor to change an operation mode to a registration mode, in order to make an object recognized and make its name registered. When considering the natural interaction between the user and the entertainment robot, however, there has been a problem that the registration of a name in response to such a clear indication is quite unnatural.